In the production of hot rolled metal goods, particularly metal strip, at the end of a production line, particularly a hot-rolled strip line, the hot metal product is collected, usually coiled up.
In the production of hot metal strip, at the end of the hot rolling line, spooling of the rolled hot strip takes place.
This wound or spooled hot metal strip is designated a hot strip bundle.
The thermal energy held by the hot strip bundle is not normally utilized in modern rolling mills. Rather, the hot strip bundles produced are placed in temporary storage pending further processing or delivery, during which the hot strip bundles cool down and release their energy to the environment.
For social and environmental reasons, reduction of the use of resources, and particularly energy, is desirable. It is also desirable to prevent, as far as possible, environmental pollution by hazardous gases, for example CO2. Furthermore, the CO2 emission from an industrial plant is of relevance to an operator of the plant with regard to the requirement for purchase and/or possible sale of emission certificates. A particularly low pollutant emission from an industrial plant compared with competitors can eventually lead to competitive advantages for an operator.
The Japanese unexamined patent application JP 57188683-A discloses an apparatus for the recovery of heat from hot strip existing in the form of a hot strip bundle. According to this prior art, the hot strip is unspooled and fed, in the form of a metal strip through a pickling tank which has heat exchange pipes and is filled with molten salts. In the unwound state, the strip gives heat up to the salt bath and said heat is conducted away through the heat exchange pipes. Water is proposed as the medium for conducting away the heat.
A disadvantage of this procedure according to the prior art is that the heat recovery is technically very complex and so far has not been realized in this way, if at all, at least not to this extent.